1. Field of the Invention
The present invention relates to a library apparatus such as a magnetic tape library apparatus. In particular, the present invention relates to a transporting mechanism employed in a library apparatus. The transporting mechanism includes a rail extending in the horizontal direction, and a grasping mechanism unit, namely a robot hand, related to the rail for relative rotation around a vertical shaft for grasping an object, namely a magnetic tape cartridge.
2. Description of the Prior Art
A magnetic tape library apparatus is well known. The magnetic tape library apparatus includes a pair of storage boxes opposed to each other. Each of the storage boxes includes cells. A magnetic tape cartridge is contained in the individual cell.
A predetermined space in the form of a parallelepiped is defined between the storage boxes. The slots of magnetic tape drives are arranged along the predetermined space. A transporting mechanism is placed within the predetermined space. The transporting mechanism includes a grasping mechanism, namely a robot hand. The robot hand is capable of transporting the magnetic tape cartridges between the cells and the slots of the magnetic tape drives. The robot hand swallows a select one of the magnetic tape cartridges from the slot when the robot hand receives the magnetic tape cartridge.
The robot hand is mounted on a rail. The robot hand is designed to move in the horizontal direction along the rail. The robot hand is in this manner positioned to a specific one of the cells or the slots of the magnetic tape drives. Simultaneously, the robot hand is designed to rotate around the vertical shaft on the rail. The robot hand is in this manner allowed to oppose its own slot to the specific one of the cells or the slots of the magnetic tape drives.
A linear motion mechanism is coupled to the robot hand on the rail for realization of the horizontal movement of the robot hand. A rotation mechanism is coupled to the robot hand for realization of the rotary movement of the robot hand. The rotation mechanism includes a pair of pulleys and a timing belt wound around the pulleys, for example. The linear motion mechanism and the rotation mechanism are individually coupled to the robot hand. The linear motion mechanism and the rotation mechanism are separately controlled. This results in a complicated structure. The production cost correspondingly increases. In addition, the timing belt inevitably suffers from deterioration due to aging.